Reliability testing opens door to secure wireless nodes

Holst Centre and Intrinsic ID have demonstrated the reliability of Physical Unclonable Function (PUF) technology based on 6T-SRAM start-up states for secure key generation. In the most extensive investigation of its type to date, researchers showed that unique and consistent keys could be generated over wide variations in environmental variables such as temperature, supply voltage and device age.

Developed by Intrinsic ID, 6T-SRAM-based PUF technology offers a way to define a unique and unpredictable identifier for a given IC based on its intrinsic physical characteristics. This identifier can be used to prevent devices being counterfeited or as a cryptographic key for a security protocol to protect data. Importantly, the technology is highly resistant to physical attacks, making it a good option for unattended wireless sensor nodes.

To test the technology’s applicability in wireless networks, Holst Centre and Intrinsic ID used a PUF based on the start-up state of 6T-SRAM – a common memory choice for sensor nodes. Through an extensive battery of reliability tests, researchers showed that unique and consistent keys could be generated across the entire range of operating conditions a node is likely to face in typical use. These include temperatures from -40 to +80°, voltage variations of ±10% and ageing effects equivalent to 5 years of continuous use.

“Wireless sensor networks in applications such as medical monitoring have to handle highly sensitive data. For these applications to become widespread, consumers will want to know their data is secure and their privacy guaranteed,” says Maryam Ashouei of Holst Centre’s ULP DSP program. “By demonstrating the reliability of PUF technology, we aim to show cryptographic keys can be protected from physical attack – offering an additional layer of consumer confidence.”

The work was presented at the 2011 ISCAS conference in Rio de Janeiro.

See also

• Ultra low power signal processing